In general, there may be two classes of electronic communications devices or simply, communications devices. A first class of communications devices may be licensed communications devices wherein the communications devices communicate over licensed spectra. Licensed communications devices typically communicate over spectrum licensed from governing or regulatory bodies and organizations, such as the Federal Communications Commission in the United States. Licensed communications devices may be able to use the licensed spectrum generally without having to consider the possibility of interference from other electronic devices or causing interference to other electronic devices operating within the licensed spectrum.
A second class of communications devices may be unlicensed communications devices wherein the communications devices communicate over spectrum that is not licensed to the devices. Unlicensed communications devices usually operate under a requirement that they do not interfere with other communications devices while being able to tolerate interference from other communications devices.
However, in some licensed spectrum, the licensed spectrum is not fully utilized and there has been a drive by regulators, developers, users, and so forth, to more fully use the valuable bandwidth. For example, in the portion of the spectrum dedicated to television transmissions, which occupies spectrum ranging from about 54 MHz to 72 MHz, about 76 MHz to 88 MHz, about 174 MHz to 216 MHz, and about 470 MHz to 806 MHz, in about 6 MHz channels, a significant portion of the available bandwidth is not being utilized. For example, within a given operating area, there may be, on average, about 5 to 20 actively transmitting television channels with the remainder of the television spectrum remaining substantially unused.
This bandwidth may be used to provide high-speed broadband access, especially in rural areas that are typically not served by cable or telephone high-speed broadband providers. The bandwidth available in the television broadcast spectrum may be used to create a wireless rural area network (WRAN). However, since this is licensed spectrum, the licensed electronic devices using the licensed spectrum must not be interfered with.
FIG. 1 is a diagram of a television broadcast network 100 having a WRAN operating in the vicinity. The television broadcast network 100 includes a television (TV) broadcast tower 105 that may be used to transmit television programs to customer premises equipment (CPE), such as television sets 110-112, and so forth. The transmissions may have a practical range (a transmission coverage area 120) that may be dependent on the operating environment, such as the terrain, the presence of other television channels broadcasting over the same frequency bands, and so forth. CPE outside of the transmission coverage area 120, such as CPE 125, may not be able to receive the television program transmissions or the quality of the received television program transmissions may not be acceptable.
The WRAN may be achieved using a WRAN broadcast tower 130. The WRAN broadcast tower 130 may transmit data to and receive data from CPE capable of data communications, such as CPE 135-136. The CPE may be able to transmit and receive directly to and from the WRAN broadcast tower 130. Additionally, transmissions from the WRAN broadcast tower 130 may be received by repeaters, such as repeater 140, that may be used to allow CPE, such as the CPE 125, outside of the transmission coverage area 120 the ability to receive information. The repeaters may also be able to transmit information back to the WRAN broadcast tower 130.
In addition to data capable CPE and data incapable CPE, there may be other licensed electronic equipment, such as wireless intercom systems, wireless video assist systems, wireless interrupted feedback systems, wireless microphones, and so forth. These licensed electronic devices may be referred to collectively as Part 74 devices. In FIG. 1, the Part 74 devices are illustrated as P74, such as P74 145. Since the Part 74 devices are licensed electronic equipment, their communications need to take precedence over the WRAN broadcast tower's communications with the data capable CPE.